CN107430275A

CN107430275A - Compact wear-type display system with homogeneous image

Info

Publication number: CN107430275A
Application number: CN201680010913.9A
Authority: CN
Inventors: Y·艾米泰
Original assignee: Lumus Ltd
Current assignee: Lumus Ltd
Priority date: 2015-02-19
Filing date: 2016-02-10
Publication date: 2017-12-01
Anticipated expiration: 2036-02-10
Also published as: US20210018755A1; IL237337B; KR20210090733A; JP2018512608A; KR20170120618A; EP4235238A3; US20230088054A1; JP6926360B2; US11531201B2; CA2976604A1; EP3587916B1; JP2024020240A; CA2976604C; RU2717897C2; JP6585727B2; CA3128963C; EP3259523B1; CN112198662A; US20180039082A1; RU2017129358A

Abstract

A kind of Optical devices are disclosed, it includes：It includes：Transparent substrates, it has input hole, delivery outlet, at least two main surfaces and edge；Optical element, it is used to light wave is coupled into substrate by total internal reflection；At least one portion reflecting surface, it is located between two main surfaces of transparent substrates, for light wave partly to be reflected into substrate；First transparent panel, it has at least two main surfaces, is attached to the main surface for the transparent substrates for limiting interface plane a main surface optical of the transparent panel；And light beam breakcoating, it is coated in the interface plane between substrate and transparent panel, wherein the light wave being coupling in inside transparent substrates partly reflects from interface plane and partially passed through wherein.

Description

Compact wear-type display system with homogeneous image

Technical field

The present invention relates to substrate-guided formula Optical devices, more particularly to include by public transparent substrates (also referred to as light guide Learn element (LOE)) carrying multiple reflecting surfaces device.

It is (such as wear-type and head-up display, cell phone, tight that the present invention can be implemented as being advantageous to many imaging applications Gather escope, 3-D displays, compact beam expander) and non-imaged apply (such as flat-panel indicators, Compact illuminator And scanner).

Background technology

One of important application of compact optical element is in head mounted display, and wherein optical module is both used as imaging Lens are used as combiner again, and wherein two dimensional display is imaged onto infinity and is reflected to the eyes of observer.Display can With directly from such as cathode ray tubes (CRT), liquid crystal display (LCD), organic LED array (OLED) or scanning source Obtain with the spatial light modulator (SLM) of similar device etc, or obtained indirectly by means of relay lens or fibre bundle.Display Device includes being imaged onto infinity and by means of the reflection as non-perspective and the combiner of fluoroscopy application by collimation lens respectively Or partially reflecting surface is delivered to element (pixel) array in the eyes of observer.Generally, conventional Free Space Optics mould Block is for these purposes.Unfortunately, increase with the expectation visual field (FOV) of system, this conventional optical module becomes more Greatly, it is heavier, huger, therefore be also unpractical even for the device of medium-performance.This is the main of various displays Shortcoming, it is particularly especially true in the wear-type application that system must be as light as possible and compact.

The effort for being directed to compactedness result in several different complicated optical solutions, and its one side is for most of Practical application is still not compact enough, and on the other hand significant drawback in terms of manufacturability be present.In addition, produced by these designs It is generally very small that the eye of raw optical look angle moves box (EMB) --- typically smaller than 8mm.Therefore, even if the performance of optical system is right It is also very sensitive relative to the small movement of the eyes of beholder in optical system, and do not allow enough pupil movements to facilitate Text is read from such display.

Be included in publication number WO01/95027, WO03/081320, WO2005/024485, WO2005/024491, WO2005/024969、WO2005/124427、WO2006/013565、WO2006/085309、WO2006/085310、WO2006/ 087709、WO2007/054928、WO2007/093983、WO2008/023367、WO2008/129539、WO2008/149339、 WO2013/175465, IL232197, the teaching in IL235642, IL236490 and IL236491 are led to the name of applicant Cross and be incorporated herein by reference.

The content of the invention

Relative to other application, the present invention is particularly helpful to the design of the LOE closely on head mounted display And manufacture.The present invention allows relatively wide FOV and relatively large eye to move box value.Resulting optical system provides greatly Type high quality graphic, it is also adapted to the big movement of eyes.Optical system provided by the invention is particularly advantageous, because it is than existing There is the embodiment of technology more compact and even can also easily be incorporated into the optical system with special configuration.

Further application of the invention is to provide a kind of compact display with wide FOV, for mobile phone, holds and answers With (such as cell phone).In the Wi-Fi (Wireless Internet Access) market of today, enough bandwidth can be used for complete transmission of video.Limit Factor processed maintains the display quality in end user's device.Mobility requirement limits the physical size of display, and result is Display directly perceived, and image viewing quality is poor.The present invention realize with very big virtual image physically closely Display.This is a key feature in mobile communication (particularly mobile internet access), solves it and actual implements One of major limitation.Therefore, the present invention can watch full format interconnection in the small handheld devices of such as cell phone etc The digital content of web page.

Therefore, according to specific requirement, extensive purpose of the invention is to mitigate state-of-the-art compact optical display device Shortcoming, and provide with the other optical components and system for improving performance.

Therefore, according to the present invention, there is provided a kind of Optical devices, it includes：Transparent substrates, it has input hole, output Hole, at least two main surfaces and edge；Optical element, it is used to light wave is coupled into substrate by total internal reflection；At least One partially reflecting surface, it is located between two main surfaces of transparent substrates, for light wave partly to be reflected into substrate；The One transparent panel, it has at least two main surfaces, is attached to a main surface optical of the transparent panel and limits interface plane The main surface of transparent substrates；And light beam breakcoating, it is coated in the interface plane between substrate and transparent panel, wherein coupling The light wave inside transparent substrates is closed partly to reflect and partially passed through wherein from interface plane.

Brief description of the drawings

With reference to some preferred embodiments, the present invention is described with reference to following illustrative accompanying drawing, so as to more comprehensively geographical The solution present invention.

When specifically referring in detail to accompanying drawing, emphasize that shown details only discusses this hair as example and being merely to illustrate property The purpose of bright preferred embodiment, and be considered as to most useful and easy in terms of the principle and concept of the present invention providing Presented under the reasons why description of understanding.In this respect, it is not attempt to illustrate in greater detail more essential to the invention than basic comprehension The CONSTRUCTED SPECIFICATION of the present invention.With the description of accompanying drawing the several of the present invention how are practically carrying out using as those skilled in the art The direction of kind form.

In the accompanying drawings：

Fig. 1 is the side view of the light-guide optical element of example prior-art；

Fig. 2A and 2B is the figure of the detailed sectional view for the exemplary array for illustrating selective reflecting surface；

Fig. 3 is the schematic sectional view according to the reflecting surface with two different incident rays of the present invention；

Fig. 4 illustrates the sectional view of the exemplary array on selective reflecting surface, and wherein transparent panel is attached to substrate edges；

Fig. 5 is the schematic sectional view of the reflecting surface according to the present invention in the actually active aperture for illustrating surface；

Fig. 6 illustrates the effective aperture size of the reflecting surface of the function as rink corner for exemplary L OE；

Fig. 7 illustrates the detailed of the reflectivity of the exemplary array from selective reflecting surface for three different visual angles Sectional view；

Fig. 8 illustrates the required distance between two adjacent reflective surfaces of the function as rink corner for exemplary L OE；

Fig. 9 is another schematic sectional view according to the reflecting surface with two different incident rays of the present invention；

Figure 10 illustrates the exemplary array on the selective reflecting surface with the wedge-shaped transparent panel for being attached to substrate edges Sectional view；

Figure 11 be according to another schematic sectional view of the reflecting surface with two different incident rays of the present invention, Wherein two-beam line reflects from two partially reflecting surfaces；

Figure 12 be according to another schematic sectional view of the reflecting surface with two different incident rays of the present invention, Wherein the two-beam line is coupled into remote LOE and is coupled out from LOE adjacent to each other；

Figure 13 A and 13B are the schematic sectional views on the light beam separation surface inside embedded light-guide optical element；

Figure 14 is light beam point of the diagram for the function as incident angle of the exemplary angular sensitive coating of s polarized lightwaves From the curve map of the reflectance curve on surface；

Figure 15 is light beam point of the diagram for the function as incident angle of the exemplary angular sensitive coating of s polarized lightwaves From another curve map of the reflectance curve on surface；

Figure 16 is embedded in the schematic section on two different light beam separation surfaces inside light-guide optical element；

Figure 17 is built-in another schematic sectional view on the light beam separation surface inside light-guide optical element, wherein saturating Manufacture partially reflecting surface inside bright lamina affixad；And

Figure 18 A and 18B are built-in the another schematic of the embodiment on the light beam separation surface inside light-guide optical element Sectional view, wherein it is diffraction optical element to be coupled into and be coupled out element.

Embodiment

Fig. 1 illustrates the sectional view of the light-guide optical element (LOE) according to the present invention.First reflecting surface 16 is by positioned at dress The collimating display 18 that the light source (not shown) in face is sent is postponed to illuminate.Reflecting surface 16 reflects the incident light from source, so that Obtain the inside that light is trapped in planar substrates 20 by total internal reflection.After several secondary reflections on surface 26,27 of substrate are left, Captured light wave reaches the array of partially reflecting surface 22, and it will be optically coupled into the observation with pupil 25 from substrate In the eyes 24 of person.Here, LOE input surface will be defined as inputting light wave and enter LOE surface by it, and LOE Output surface leaves LOE surface by captured light wave is defined as by it.In addition, LOE input hole will be considered as The part on the input surface that input light wave actually passes through when inputting LOE, and LOE delivery outlet will be considered as output light-wave A part for the output surface actually passed through when leaving LOE.In Fig. 1 in the case of shown LOE, input and output surface All overlapped with lower surface 26, it is envisioned that wherein input and image light waves can be located on the opposite side of substrate or be located at Other configurations on one of LOE edge.Assuming that the center light wave in source along perpendicular to the direction of substrate surface 26 from the coupling of substrate 20 Conjunction comes out, and partially reflecting surface 22 is flat, and it is α to couple off-axis angle of the light wave inside substrate 20_in, then reflection Angle [alpha] between surface and the normal of base plan_sur2For：

It will be seen from figure 1 that captured light reaches reflecting surface from two different directions 28,30.It is specific at this In embodiment, after even-numbered reflections are sent from substrate surface 26 and 27, captured light is from one in these directions 28 Individual arrival partially reflecting surface 22, wherein the incident angle β ref between captured light and the normal of reflecting surface are：

After odd number secondary reflection is sent from substrate surface 26 and 27, captured light reaches from second direction 30 to be reflected Surface, wherein off-axis angle are α '_in=180 ° of-α_in, and the incident angle between the light and the normal of reflecting surface captured For：

The light that wherein negative sign represents captured is incident on the opposite side of partially reflecting surface 22.

As shown in fig. 1, for each reflecting surface, the surface is reached from direction 30 first per beam light, it is some of Light is incident on the surface from direction 28 again.In order to prevent undesirable reflection and ghost image, it is important that for being incident on tool There is the light on the surface of second direction 28, reflectivity can be ignored.

The major issue that must take into consideration is the actually active region of each reflecting surface.Due to reaching each selectivity (some light interact the different reflected orders of the different light of reflecting surface in the early stage not with selective reflecting surface In the case of reach；Other light reach after the reflection of one or many parts) reason, and may be in gained image There is potential inhomogeneities.The effect illustrates in fig. 2.Assuming that such as α_in=50 °, then light 80 at point 82 with first Partially reflecting surface 22 is intersecting.The incident angle of light is 25 °, and a part for light ray energy is coupled out from substrate. Then, light crosses same selective partially reflecting surface at point 84 with 75 ° of incident angle, is reflected without obvious, Then crossed again with 25 ° of incident angle at point 86, another part energy of wherein light is coupled out from substrate.Phase Instead, the light 88 shown in Fig. 2 B is only subjected to primary event 90 from same surface.Occur in addition on other parts reflecting surface Multiple reflections.

Fig. 3 illustrates this non-uniform phenomenon with the detailed sectional view of partially reflecting surface 22, the partially reflecting surface 22 will capture being optically coupled into the eyes 24 of observer in substrate.As can be seen that light 80 is from close to as reflection table Face 22 and the upper surface 27 of the line 100 of the intersection of upper surface 27 reflect away.Because the light is not incident on reflecting surface 22, So after the double reflection from two outer surfaces, its brightness is kept at first time incidence identical and that it is at surface 22 In putting at 102.Now, light wave is partially reflected, and light 104 is coupled out from substrate 20.For positioned at light 80 Other light of such as light 88 of underface etc, the first time at surface 22 are incident on before it meets with upper surface 27 In putting at 106, the light section is partially reflected wherein and light 108 is coupled out from substrate.Therefore, when it enters again When penetrating on the surface 22, at the point 110 after the double reflection from outer surface 26,27, the brightness for the light being coupled out is low In adjacent ray 104.As a result, having for the left side of the point of arrival 102 is coupled into all of angle with 80 identicals at surface 22 Light has relatively low brightness.Therefore, angle specifically is coupled into for this, from the reflectivity on surface 22 actually in point 102 left side is darker.

However, it is difficult to which this species diversity in multiple intersecting effect is fully compensated, actually human eye has been tolerated and still not noted The notable brightness change of meaning.For nearly eyes display, eyes by the light occurred from single visual angle assemble on the retina one On individual point, and because the response curve of eyes is logarithm, so the very little change of display brightness (if any) will Will not be very notable.Therefore, the figure of high quality is also undergone even for the moderate illumination uniformity in display, human eye Picture.Required moderate homogeneity can be easily realized using the element shown in Fig. 1.For the system with big FOV, , it is necessary to which a considerable amount of partially reflecting surface is to realize desired delivery outlet in the case of needing big EMB.As a result, due to Some reflecting surfaces it is repeatedly intersecting caused by inhomogeneities become more main (especially for certain apart from eyes The display (such as head-up display) of distance), and this inhomogeneities can not receive.For these situations, it is necessary to more be The method of system overcomes this inhomogeneities.

Very little is contributed because " dark " of partially reflecting surface 22 is partly coupled out for captured light wave from substrate, So the influence of their optical properties to LOE can only be negative, i.e. there will be compared with dark portion in the delivery outlet of the system Point, and dark fringe will be present in image.However, the transparency of each reflecting surface is on the light wave from outer scene Uniformly.Therefore, if set between reflecting surface it is overlapping to compensate the relatively dark-part in delivery outlet, from output scene The light through these overlapping regions will suffer from dual decay, and will produce darker striped in outer scene.It is this Phenomenon not only significantly reduces the performance of the display (such as head-up display) at a certain distance from eyes, Er Qiexian Reduce the performance of near-to-eye with writing, therefore can not utilize.

Fig. 4 illustrates the embodiment for overcoming this problem.Only partially reflecting surface 22a, 22b, 22c " bright " part is embedding Enter in substrate, i.e., reflecting surface 22a, 22b, 22c no longer intersects with bottom major surface 26, but terminates the short side on the surface.By In the end of reflecting surface in LOE length it is adjacent to each other, therefore gap is there will be no in projected image, and due to table Between face be not present it is overlapping, so there will be no gap in external view.Building this LOE has several ways, one of them It is that the transparent panel 120 (preferably passing through optical veneering) with thickness T is attached in the effective coverage of substrate.In order to correct The effective coverage of reflecting surface 22 is used only in mode, it is important that calculates actually active region and the plate of each partially reflecting surface 120 required thickness T.

As shown in Figure 5, bright aperture Ds of the reflecting surface 22n in the plane of outer surface 26_n, as being coupled into angle α_inFunction, be：

Due to capturing angle [alpha]_inWhich can change as FOV function, it is therefore important that knowing with angle relation Each reflecting surface 22n, to calculate its effective aperture.

Fig. 6 illustrates the effective aperture of the function of the rink corner as following systematic parameter：Substrate thickness d=2mm, substrate folding Penetrate rate v=1.51, and partially reflecting surface angle [alpha]_sur=64 °.When considering visual angle, it is noted that resulting image is not With different piece of the part from partially reflecting surface.

Fig. 7 is the sectional view of the compact LOE display systems based on the configuration proposed, and which illustrates the effect.Here, The monoplane light wave 112 for representing certain viewing angles 114 only illuminates one of whole array of partially reflecting surface 22a, 22b and 22c Point.Therefore, for each point in partially reflecting surface, nominal visual angle is limited, and according to the angle calculation reflecting surface Required effective coverage.The accurate detailed design of the effective coverage of various partially reflecting surfaces is carried out as follows：For each specific table Face, draw the light from the left hand edge on surface to the center of specified eye pupil 25 and (consider the folding caused by Snell laws Penetrate).The direction calculated is arranged to nominal incidence direction, and specific effective coverage is calculated according to the direction.

As shown in Figure 5, the exact value of reflecting surface effective coverage can be used for the bright part for determining each reflecting surface 22n Left hand edge 102 and lower surface 26 between various distance T.Larger effective coverage determines less distance between the surface.Should be away from From the thickness of the plate 120 (Fig. 7) for the lower surface for representing be attached to LOE.As shown in Figure 5, as being coupled into angle [alpha]_in The distance T of function be：

T=d-D_n·cot(α_sur) (5)

Fig. 8 is illustrated for the plate 120 with function identical parameter, as rink corner above with reference to set by Fig. 6 Required thickness T.It is worth that thickness T is arranged into calculated maximum to ensure to avoid dark fringe phenomenon in the picture.Set Too thick plate 120 will cause reverse effect, i.e., occur in bright wisp print image.

As shown in Figure 9, two-beam line 122 and 124 is coupling in substrate 20.This two-beam line is putting 126 Hes respectively Reflected at 128 from surface 22a parts.However, only light 122 is incident on second surface 22b and at which at point 130 It is partially reflected, and light 124 skips surface 22b without any reflection.As a result, it is incident at point 134 on the 22c of surface The brightness of light 124 is higher than the brightness of the light 122 at point 132.Therefore, the brightness for being coupled out light 138 from point 134 is high In the brightness for the light 136 being coupled out from point 132, and bright fringes will appear from the picture.Therefore, it should select thickness T's Exact value is to avoid the dark and bright fringes in image.

As shown in Figure 10, for realizing the possibility embodiment of required structure (wherein the thickness T of plate 120 depends on visual angle) To be the main uneven surface row of construction wedge-shaped substrate 20'(two of which).Complementary transparent clapboard 120' preferably passes through optical cement Conjunction is attached on substrate, and to cause combining structure to form complete cuboid, i.e., final LOE two outer main surfaces are put down each other OK.However, this method has some shortcomings.First, wedge-shaped LOE manufacture craft is more more complicated and cumbersome than parallel.In addition, should Solution is effective, visual angle and lateral attitude in this small EMB in base plan for the system with small EMB Between good matching be present.However, for the system with big EMB, i.e. can significantly be moved along axis of pitch in eyes In the case of, there will not be good adjustment between visual angle and plate 120' actual (real) thickness.Accordingly, it is possible to it can see in the picture To dark or bright fringes.

Dark or bright fringes occurs being not limited to produce the phenomenon caused by structure of the partially reflecting surface in LOE Surface.With reference to as shown in figure 3, it is less than by the brightness of the coupling light 88 of surface 22a reflections twice in point 110 in point 102 The brightness of light 80 of the place only from surface 22a reflections once.As a result, the brightness of back wave 112 is bright less than adjacent ray 104 Degree.However, as shown in Figure 11, the brightness not only from surface 22a back wave is different, and transmitted ray 140 and 142 Brightness is also different.As a result, the brightness of the reflection light 144 and 146 from surface 22b will be with identical at point 148 and 150 respectively Mode it is different, and will also produce dark fringe in the region of image.Certainly, this dissimilarity between light will continue Next partially reflecting surface is traveled in LOE.As a result, because each partially reflecting surface is produced according to accurate incident angle The dark or bright fringes of raw their own, so for the LOE with a large amount of partially reflecting surfaces, substantial amounts of dark and bright fringes will be tired out Product is in the distal edge of LOE delivery outlet, therefore picture quality is by severe exacerbation.

Another uneven source of image can be the inhomogeneities for the image ripple being coupled into LOE.Generally, light is worked as When two edges in source have slightly different intensity, if any, also hardly observed person notices for this.Such case It is entirely different for the image for being coupling in substrate and being gradually coupled out, as in LOE.As shown in Figure 12, Two-beam line 152 and 154 is located at the edge of plane wave 156, and the plane wave 156 is derived from the identical point in the (not shown) of display source. Assuming that the result as non-perfect imaging system, and the brightness of light 152 is less than the brightness of light 154, then due between light It is remote, and will be difficult to see that by the direct observation of plane wave 156 this unequal.However, in LOE20 is coupled into it Afterwards, the situation is changed.When light 154 is irradiated to the positive right side of the parting line 156 between reflecting surface 16 and bottom major surface 26 During the reflecting surface 16 of side, right side light 152 is reflected from surface 16, is totally reflected from upper surface 27, is then incident on parting line On the lower surface 26 of 158 directly to the left.As a result, this two-beam line 152 and 154 is adjacent to each other in LOE 20 and propagated.Respectively Correspondingly there is different brightness from light 152 and 154 and from two emergent rays 160 and 162 of surface 22a reflections.So And it is different from input light wave 156, two different light are adjacent to each other, and this dissimilarity will easily be counted as figure Dark fringe as in.This two-beam line 164,165 will be propagated together adjacent to each other inside LOE, and will be in each position Place forms the filaments of sun, them is coupled together together.Certainly, the best approach of this inhomogeneities is avoided to be to ensure that entrance All coupling light waves in LOE have uniform brightness on whole FOV whole input hole.For with big FOV and width For the system of input hole, this requirement may be extremely difficult.

As shown in Figure 13 A and 13B, this non-uniformity problem can be by the way that transparent panel to be attached to LOE main surface One of solve, as described above with reference to figure 4.However, in this embodiment, light beam breakcoating 166 is applied to LOE 20 Interface plane 167 between transparent panel 120.As shown in FIG. 13A, two-beam line 168 and 170 is coupling in substrate 20.Only There is light 168 to be incident at point 172 on Part I reflecting surface 22a and partly reflect at which, and light 170 is jumped Surface 22a is crossed without any reflection.As a result, it is assumed that two-beam line has identical brightness when being coupled into LOE, then from The light 170 that bottom major surface 26 reflects upwards has higher brightness than the light 168 being reflected down from upper surface 27.This two beam Light intersects each other at the point 174 in interface plane 167.Due to the reason of light beam breakcoating being coated on, Every in two beam Intersecting light rays a branch of is partially reflected and partially across coating.Therefore, two-beam line is between them Positive energy exchange, and the light 176 and 178 come out from intersection point 174 has similar brightness, and it is substantially two beam incident rays 168 and 170 mean flow rate.In addition, the light at joining 180 and 182 with other two-beam line (not shown) exchange energy Amount.As the result of this energy exchange, the two beam reflection lights 184 and 186 from surface 22b are by with substantially similar bright Degree, and bright fringes effect will significantly improve.

Similarly, as shown in Figure 13 B, two-beam line 188 and 190 is coupling in substrate 20.However, only light 188 It is incident at point 192 on Part I reflecting surface 22a and before being reflected by upper surface 27 there by partly anti- Penetrate.As a result, it is assumed that two-beam line has identical brightness when being coupled into LOE, then is reflected down from top major surface 27 Light 190 has the brightness higher than light 188.However, this two-beam line at the point 194 in interface plane 167 that This intersecting and positive energy exchange there.In addition, this two-beam line positioned at light beam separation surface 167 on point 196 and 198 at Other ray intersections.As a result, the light 200 and 202 from surface 22a reflections and the light 204 and 206 from surface 22b reflections By with essentially identical brightness, therefore dark fringe effect will significantly reduce.The uniformity of this improved brightness effects is also fitted For dark and bright fringes caused by the non-uniform illumination by LOE input hole.As a result, the light wave being trapped in inside LOE Luminance Distribution on LOE delivery outlet substantially than on input hole evenly.

As shown in FIG. 13A, from the light 184,186 of surface 22a reflections before being coupled out from LOE, with light beam point It is intersecting from surface 167.As a result, because for fluoroscopy application the surface for the light wave that exits substrate 20 be also it is transparent and And be also transparent for the light wave from outer scene, i.e., light wave is entered through plane 167 and with higher with small incident angle Angle part reflection is penetrated, so simple reflectance coating can not easily be applied to surface 167.Generally, it is this pass through enter Firing angle degree is between 0 ° and 15 °, and the incident angle of part reflection is between 40 ° and 65 °.Further, since light exists Interface plane 167 is repeatedly passed through during LOE internal communications, so the absorption of coating should be negligible.As a result, it is impossible to use Simple metal coating, and the thin dielectric membrane coat with the high grade of transparency must be used.

Figure 14 is illustrated as on the Three Represents wavelength in photopic vision region, i.e. 470nm, 550nm for s polarizations With the reflectance curve of the function of 630nm incident angle.As illustrated, for s polarized lightwaves, it is possible to achieve between 40 ° And the low reflection under the partial reflectance (between 45% and 55%) and small incident angle under the big incident angle between 65 ° The required behavior of rate (being less than 5%).For p-polarization light wave, due to close to Brewster (Brewster) angle, it is impossible to Essence reflection is realized under incident angle between 40 ° and 65 °.Due to being generally used for the polarization of the imaging system based on LOE It is s polarizations, therefore can comparatively easy applies required beam splitter.However, due to light beam breakcoating for Low incidence angle is incident in interface surface and should be basic for the substantially unpolarized light wave from outer scene On be transparent, so for p-polarization light wave, the coating should have antiradar reflectivity (being less than 5%) under small incident angle.

The difficulty still having is that LOE 20 is assembled by several different parts.Because manufacturing process is usually directed to admittedly Determine optical element, and due to required angular-sensitive reflectance coating only is coated into light after LOE 20 main body is completed Lead surface, it is impossible to which utilization may damage the hot coating procedure of routine of gluing area.Novel thin film technology and ion Assistant coating process can also be used for cold working.The needs of heater block are eliminated, glue component is coated safely.One kind substitutes Scheme is then coating that can be required is solidified in place, come simple by using conventional hot coating procedure Ground is coated to the transparent panel 120 adjacent with LOE 20.Obviously, this alternative is only when transparent panel 120 is less thin thus may It can just be used when being deformed during coating procedure.

When designing light beam separating mechanism as described above, it should be taken into account that some problems：

A. because the light being trapped in LOE is not only totally reflected from main surface 26 and 27, and reflected from interior section Interface plane 167 is totally reflected, thus all three surfaces in these surfaces by it is parallel to each other with ensure couple light will be in LOE Inside keeps them original to be coupled into direction.

B. as shown in Figure 13 A and 13B, transparent panel 120 is thinner than original LOE 20.However, different from Fig. 7-10 In be not coated with (wherein the thickness of plate 120 optimizes critically important for uniformity) is considered caused by cladding plate, here can be according to other Consider to select the thickness of coated board.On the one hand, it is easier to manufacture, coat and glued thicker plate.On the other hand, utilization is thin Plate, the effective volume for the LOE 20 that actually light wave is coupled out from substrate are bigger for given substrate thickness.This Outside, the precise proportions between plate 120 and LOE 20 thickness may influence the energy exchange processes in substrate.

C. should be use up for whole photopic vision region typically for the beam splitter specified for full-colour image, reflectivity curve May be uniform, to stop color effect.However, due in the configuration shown in the present invention, various light are from the couplings of LOE 20 Intersected each other many times before closing out, so this requirement has receded into the background.Certainly, light beam breakcoating should consider coupling The whole wave spectrum of image is closed, but can tolerate that the color of part reflectivity curve is flat according to the various parameters of system Degree.

D. the reflective-transmissive ratio of light beam breakcoating is not necessarily 50%-50%.It can be realized using other ratios Dark and compared with the required energy exchange between bright light rays.In addition, as shown in Figure 15, it can be separated using simpler light beam Coating, wherein reflectivity from incident angle be 40 ° when 35% progressively increase to when incident angle is 65 ° 60%.

The quantity on the light beam separation surface being e. added in LOE is not limited to one.As shown in Figure 16, another transparent panel 208 may be glued to LOE upper surface, wherein by similar light beam breakcoating be coated between LOE 20 and upper plate 208 it Between interface plane 210 on, to form the Optical devices that surfaces are separated with two light beams.Here, the uneven light of two beams 212 and 214 with other intersecting for light at point 216 and 217 and at point 215 in coated interface plane 210 that This is intersecting.With the exception of this, this is the intersection point in lower light beam separating interface plane 167.As a result, it is contemplated that reflection light 218 and 220 Uniformity the uniformity than Figure 13 A and 13B embodiment is more preferable.Certainly, there is the LOE of two light beam separating interface planes Manufacture method than only have single plane LOE manufacture method it is more difficult.Therefore, it should only very tight to non-uniformity problem The system of weight accounts for.As previously described, it is important that all four reflecting surfaces and plane 26,27,167 and 210 should that This is parallel.

F. transparent panel 120 should not be by being made with the identical optical materials of LOE 20.In addition, LOE can be by silicate-base Material is made, and for the sake of security, hyaline layer can be made up of polymer-based material.Certainly, it should be noted that ensure outer surface Optical quality and avoid the deformation of transparent panel.

G. up to the present, all assume that transparent panel is blank.However, as shown in Figure 17, it can be made inside plate 120 Partially reflecting surface 222a and 222b are made, to increase LOE volume available.These surfaces should be strictly parallel to existing surface 22a and 22b and with identical azimuthal orientation.

Above-described embodiment all various parameters (such as thickness of plate 120 and optical material, light beam breakcoating it is definite The position of property, the quantity and partially reflecting surface on light beam separation surface in LOE) there can be many different probable values. The exact value of these factors determines according to the specific requirement of the various parameters and optical quality and manufacturing cost of optical system.

Up to the present, assume that light wave passes through partially reflective surface and is coupled out from substrate, the partially reflecting surface phase Oriented for main surface with angle of inclination, and be general coated with dielectric coating.However, as shown in figure 18, exist so System, wherein light wave is utilized respectively diffraction element 230 and 232 and is coupled into substrate and is coupled out from substrate.It is above-mentioned to beg for The identical uniformity problem of opinion also should be related to this configuration.As illustrated, the two-beam line 234 of the identical point in display source It is coupled into 236 in substrate 238, the substrate 238 is located remotely from each other at two edges for being coupled into element 230 Place.The coupling elements 232 that these light are positioned adjacent to each other are coupled out.Therefore, will be easily in coupling output image In see any dissimilar part between these light.In addition, in order to verify through uniformly coupling output image, coupling output member The diffraction effect of part 232 is gradually increased.As a result, the different light from same point source may be coupled out from the element 232 To pass through the diverse location in element 232 before, therefore in the picture by with different brightness.Another uneven source It is probably because light 234 goes out substrate at the right hand edge 240 of grating 232 by part diffraction, and light 236 is being incident on grating just On the lower surface in left side, therefore not diffraction there.As a result, the institute for two beam adjacent rays 234 and 236 in grating 232 There is a coupling outgoing position, light 236 is by with higher brightness, and this difference will be readily seen that.

Figure 18 B illustrate the similar approach for solving these problems.As illustrated, transparent panel 242 is glued to substrate 238 Upper surface 244, wherein interface surface 246 are coated with the light beam breakcoating similar to above-mentioned coating.

Claims

1. a kind of Optical devices, including：

Transparent substrates, it has input hole, delivery outlet, at least two main surfaces and edge；

Optical element, it is used to light wave is coupled into substrate by total internal reflection；

At least one portion reflecting surface, it is located between two main surfaces of the transparent substrates, for by light wave partly Reflect substrate；

First transparent panel, it has at least two main surfaces, is attached to a main surface optical of the transparent panel and limits interface The main surface of the transparent substrates of plane；And

Light beam breakcoating, it is coated in the interface plane between the substrate and the transparent panel,

The light wave inside the transparent substrates is wherein coupling in partly to reflect and partially across institute from the interface plane State interface plane.

2. Optical devices according to claim 1, wherein being coupled out by the partially reflecting surface from the substrate Light wave essentially through the interface plane, without any significant reflectivity.

3. Optical devices according to claim 1, wherein the major surfaces in parallel of the transparent substrates is transparent in described first The main surface of plate.

4. Optical devices according to claim 1, wherein the light beam breakcoating has height anti-under big incident angle Rate is penetrated, and there is antiradar reflectivity under small incident angle.

5. Optical devices according to claim 4, wherein the light beam breakcoating is in the incidence between 0 ° and 15 ° There is antiradar reflectivity under angle, and there is high reflectance under the incident angle more than 40 °.

6. Optical devices according to claim 4, wherein the light beam breakcoating has under the incident angle higher than 40 ° There is the reflectivity higher than 35%, and there is the reflectivity less than 10% under the incident angle less than 15 °.

7. Optical devices according to claim 1, wherein the light beam breakcoating is applied to the transparent substrates Main surface.

8. Optical devices according to claim 7, wherein the light beam breakcoating is coated using cold coating processes.

9. Optical devices according to claim 1, wherein the light beam breakcoating is coated to first transparent panel On one surface.

10. Optical devices according to claim 4, wherein the reflectivity of the light beam breakcoating is higher than 40 ° and low The substantial constant under 60 ° of incident angle.

11. Optical devices according to claim 4, wherein the reflectivity of the light beam breakcoating is in entering higher than 40 ° It is non-constant under firing angle degree.

12. Optical devices according to claim 11, wherein the reflectivity of the light beam breakcoating is in entering higher than 40 ° Increase under firing angle degree as the function of incident angle.

13. Optical devices according to claim 4, wherein for whole photopic vision region, the light beam point under big incident angle It is substantially uniform from the reflectivity of coating.

14. Optical devices according to claim 1, wherein the transparent panel is thinner than the transparent substrates.

15. Optical devices according to claim 1, in addition to the second transparent panel, it is optically attached to the printing opacity base Plate, restriction second contact surface plane another main surface.

16. Optical devices according to claim 15, wherein coating light beam breakcoating in the second contact surface plane.

17. Optical devices according to claim 16, wherein the light beam breakcoating has height under big incident angle Reflectivity, and there is antiradar reflectivity under small incident angle.

18. Optical devices according to claim 1, wherein the transparent substrates and the transparent panel are by identical optics material Material is made.

19. Optical devices according to claim 1, wherein the transparent substrates and the transparent panel are by two kinds of different light Material is learned to be made.

20. Optical devices according to claim 1, wherein the transparent panel is made up of polymer-based material.

21. Optical devices according to claim 1, wherein for the optical element being coupled into light wave in the substrate It is diffraction element.

22. Optical devices according to claim 1, wherein described between two main surfaces of the transparent substrates At least one portion reflecting surface is diffraction element.

23. Optical devices according to claim 1, wherein described between two main surfaces of the transparent substrates At least one portion reflecting surface is oriented relative to the main surface of the substrate with angle of inclination.

24. Optical devices according to claim 23, wherein at least one portion reflecting surface is coated with electric Jie Matter coating.

25. Optical devices according to claim 1, including some reflecting surfaces, it is located at the transparent substrates Between two main surfaces, wherein the partially reflecting surface is parallel to each other.

26. Optical devices according to claim 1, wherein the Luminance Distribution for the light wave being coupling in inside the substrate is in institute State on the delivery outlet of substrate than on the input hole substantially evenly.